test: add retry logic for eventloopdelay histogram sampling

[mcollina]

Summary

Fixes flaky test-performance-eventloopdelay test on sharedlibs builds.

Problem

On some build configurations (e.g., Ubuntu 24.04 sharedlibs), the histogram may not record valid samples (min > 0) after the initial spinning period. The test fails with:

AssertionError [ERR_ASSERTION]: assert(histogram.min > 0)

The previous fix (PR #61629) added setImmediate to allow samples to be recorded, but this wasn't sufficient for all configurations.

Solution

Add a retry mechanism that checks if valid samples have been recorded (count > 0 && min > 0 && max > 0). If not, the test will spin the event loop additional times (up to 3 retries) before asserting.

This ensures the test passes on slower or differently-configured systems where event loop delay sampling may take longer to produce measurable results.

Verification

Tested locally with python3 tools/test.py --repeat 30 - all passed.

Refs: nodejs/reliability#1461

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.74%. Comparing base (4a13a62) to head (ad1c0a7).
⚠️ Report is 3 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #61796      +/-   ##
==========================================
- Coverage   89.76%   89.74%   -0.02%     
==========================================
  Files         675      675              
  Lines      204674   204674              
  Branches    39330    39325       -5     
==========================================
- Hits       183716   183689      -27     
- Misses      13235    13252      +17     
- Partials     7723     7733      +10     

see 29 files with indirect coverage changes

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